The fundamental apparatus, algorithm and method for achieving perspectively-corrected views of any selected portion of a hemispherical (or other wide angle) field of view are described in detail in the above-cited U.S. Pat. No. 5,185,667. This patent is incorporated herein by reference for its teachings. Through the use of this technology no moving parts are required for achieving pan, tilt and rotation "motions" as well as magnification. Briefly, a wide angle field of view image is captured into an electronic memory buffer. A selected portion of the captured image containing a region of interest is transformed into a perspective correct image by an image processing computer. This provides direct mapping of the wide angle image region of interest into a corrected image using an orthogonal set of transformation algorithms. The viewing orientation, and other viewing perimeters, are designated by a command signal generated by either a human operator or a form of computerized input. The transformed image is deposited in a second electronic memory buffer where it is then manipulated to produce the output image as requested by the command signal.
The invention of that patent was envisioned as being primarily a unitary system in that all components were located in close proximity. Even in the subsequent patent applications (Ser. No. 08/014,508, above-cited, and Ser. No. 08/068,776, filed Jun. 1, 1993) of related technology, the inventions were envisioned as having all components in close proximity. As such, there could be ready verification of operation, alignment and any needed adjustment.
There are applications, however, for the same type of omniviewing of wide angle images where there is a substantial distance between where the initial image occurs and the location where the perspectively-corrected views are to be utilized. For example, in the teleconferencing art some type of display is exhibited at one location, and persons at a distant location desire to view all or a selected portion of the display. According to common practice prior to the development of the basic system for providing a selected image without the use of moving components, control signals had to be sent to the site of the display so as to make necessary adjustments to equipment at that site so as to select a portion of the display, or enhance a selected portion, for use of the view at the distant location. Further, it is often desirable to have a plurality of viewers each individually wishing to observe selected portions of the image, with those plurality of viewers potentially scattered at separate viewing locations. The prior art for this situation would require a plurality of cameras (video sources) and a plurality of control signals being sent to the site of the images, and each viewer taking a selected time for their individual viewing.
Accordingly, it is an object of the present invention to utilize variations on the technology of production of perspective-corrected views, at one or more locations, of at least portions of an overall image occurring at a distant location.
It is another object of the present invention to provide for the generation of a wide angle image at one location and for the transmission of a signal corresponding to that image to another location, with the received transmission being processed so as to provide a perspective-corrected view of any selected portion of that image at the other location.
It is also an object of the present invention is to provide for the generation of a wide angle image at one location and for the transmission of a signal corresponding to that image to another location, with the received transmission being processed so as to provide at a plurality of stations a perspective-corrected view of any selected portion of that image, with each station selecting a desired perspective-corrected view.
A further object of the present invention is to provide for the generation of a wide angle image at one location and for the transmission of a signal corresponding to that image to a plurality of other locations, with the received transmission at each location being processed so as to provide a perspective-corrected view of any selected portion of that image, with the selected portion being selected at each of the plurality of other locations.
These and other objects of the present invention will become apparent upon a consideration of the drawings referred to hereinafter, and the detailed description thereof.